diff --git a/src/bits_intern.h b/src/bits_intern.h
index 4007ee10a5..8bcb65e8f4 100644
--- a/src/bits_intern.h
+++ b/src/bits_intern.h
@@ -13,6 +13,8 @@
 
 #include "system.h"
 
+#include <string.h>
+
 
 #define ALL_BITS_UINT  (~(UInt)0)
 
diff --git a/src/boehm_gc.c b/src/boehm_gc.c
index 62d012f10f..6255923377 100644
--- a/src/boehm_gc.c
+++ b/src/boehm_gc.c
@@ -33,6 +33,11 @@
 #include "hpc/thread.h"
 #endif
 
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
 #ifndef WARD_ENABLED
 
 static inline Bag * DATA(BagHeader * bag)
diff --git a/src/common.h b/src/common.h
index 05ea4c6345..5732a4021b 100644
--- a/src/common.h
+++ b/src/common.h
@@ -14,12 +14,7 @@
 #include "config.h"
 
 #include <assert.h>
-#include <limits.h>
-#include <setjmp.h>
 #include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 
 #include "debug.h"
 
diff --git a/src/debug.c b/src/debug.c
index df32fe1213..e28d15672c 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -28,6 +28,9 @@
 #include "hpc/region.h"
 #endif
 
+#include <stdio.h>
+#include <stdlib.h>
+
 #if defined(HAVE_BACKTRACE) && defined(GAP_PRINT_BACKTRACE)
 #include <execinfo.h>
 #include <signal.h>
diff --git a/src/error.c b/src/error.c
index bbf1301046..277cecf83f 100644
--- a/src/error.c
+++ b/src/error.c
@@ -35,6 +35,8 @@
 #include "hpc/thread.h"
 #endif
 
+#include <stdio.h>
+
 
 static Obj ErrorInner;
 static Obj ERROR_OUTPUT = NULL;
diff --git a/src/funcs.c b/src/funcs.c
index cb78eb8da9..2e03982f73 100644
--- a/src/funcs.c
+++ b/src/funcs.c
@@ -39,6 +39,9 @@
 #include "hpc/thread.h"
 #endif
 
+#include <stdlib.h>
+
+
 static ModuleStateOffset FuncsStateOffset = -1;
 
 struct FuncsModuleState {
diff --git a/src/gasman.c b/src/gasman.c
index bf6b00ed8c..a3629b687a 100644
--- a/src/gasman.c
+++ b/src/gasman.c
@@ -123,6 +123,8 @@
 
 #include "bags.inc"
 
+#include <string.h>
+
 #ifdef GAP_MEM_CHECK
 #include <sys/mman.h>
 #endif
diff --git a/src/gvars.c b/src/gvars.c
index f13c1d68f7..7a653fef33 100644
--- a/src/gvars.c
+++ b/src/gvars.c
@@ -48,6 +48,8 @@
 #include <pthread.h>
 #endif
 
+#include <stdio.h>
+
 
 #ifdef HPCGAP
 #define USE_GVAR_BUCKETS
diff --git a/src/hookintrprtr.c b/src/hookintrprtr.c
index c31abe8dd6..c4387d1561 100644
--- a/src/hookintrprtr.c
+++ b/src/hookintrprtr.c
@@ -22,6 +22,8 @@
 
 #include "hpc/thread.h"
 
+#include <string.h>
+
 
 /* List of active hooks */
 struct InterpreterHooks * activeHooks[HookCount];
diff --git a/src/hpc/aobjects.c b/src/hpc/aobjects.c
index b530eda129..f3ab3400b8 100644
--- a/src/hpc/aobjects.c
+++ b/src/hpc/aobjects.c
@@ -33,6 +33,8 @@
 #include "records.h"
 #include "stringobj.h"
 
+#include <stdlib.h>
+
 
 static Obj TYPE_ALIST;
 static Obj TYPE_AREC;
diff --git a/src/hpc/misc.c b/src/hpc/misc.c
index aa5b9aa949..358e150759 100644
--- a/src/hpc/misc.c
+++ b/src/hpc/misc.c
@@ -10,6 +10,7 @@
 
 #include "hpc/misc.h"
 
+#include <stdlib.h>
 #include <string.h>
 
 /****************************************************************************
diff --git a/src/hpc/thread.c b/src/hpc/thread.c
index 1b2feaa283..b070e82ac9 100644
--- a/src/hpc/thread.c
+++ b/src/hpc/thread.c
@@ -28,6 +28,7 @@
 #include <errno.h>
 #include <pthread.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <sys/mman.h>
 #include <unistd.h>
 
diff --git a/src/hpc/threadapi.c b/src/hpc/threadapi.c
index da94225292..19a976d92a 100644
--- a/src/hpc/threadapi.c
+++ b/src/hpc/threadapi.c
@@ -39,8 +39,9 @@
 #include "hpc/tls.h"
 #include "hpc/traverse.h"
 
-#include <stdio.h>
 #include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include <sys/time.h>
 
 #include <pthread.h>
diff --git a/src/hpc/tls.c b/src/hpc/tls.c
index 1e309d32b6..2f831f6ef2 100644
--- a/src/hpc/tls.c
+++ b/src/hpc/tls.c
@@ -11,6 +11,8 @@
 #include "gapstate.h"
 #include "hpc/thread.h"
 
+#include <string.h>
+
 #ifdef USE_NATIVE_TLS
 
 __thread GAPState TLSGAPtate;
diff --git a/src/io.c b/src/io.c
index 1c91af8e13..768ffd9706 100644
--- a/src/io.c
+++ b/src/io.c
@@ -41,6 +41,8 @@
 #include "hpc/aobjects.h"
 #endif
 
+#include <limits.h>
+
 
 /****************************************************************************
 **
diff --git a/src/libgap-api.c b/src/libgap-api.c
index f804dcc2f5..c72221837e 100644
--- a/src/libgap-api.c
+++ b/src/libgap-api.c
@@ -36,6 +36,8 @@
 #include "streams.h"
 #include "stringobj.h"
 
+#include <stdio.h>
+
 static BOOL UsingLibGap = FALSE;
 
 BOOL IsUsingLibGap(void)
diff --git a/src/macfloat.c b/src/macfloat.c
index d8f2916387..5e1a50b1b1 100644
--- a/src/macfloat.c
+++ b/src/macfloat.c
@@ -33,6 +33,10 @@
 #include "stringobj.h"
 #include "sysstr.h"
 
+#include <stdio.h>
+#include <stdlib.h>
+
+
 #define RequireMacFloat(funcname, op) \
     RequireArgumentCondition(funcname, op, IS_MACFLOAT(op), \
         "must be a macfloat")
diff --git a/src/modules.c b/src/modules.c
index 147019c264..87b43a9701 100644
--- a/src/modules.c
+++ b/src/modules.c
@@ -41,6 +41,8 @@
 #include <dlfcn.h>
 #endif
 
+#include <stdio.h>
+
 
 /****************************************************************************
 **
diff --git a/src/objects.c b/src/objects.c
index ae134cc96a..3368cf30b6 100644
--- a/src/objects.c
+++ b/src/objects.c
@@ -38,6 +38,9 @@
 #include "hpc/traverse.h"
 #endif
 
+#include <stdio.h>
+#include <stdlib.h>
+
 
 enum {
     MAXPRINTDEPTH = 64,
diff --git a/src/opers.c b/src/opers.c
index 4eff49e7f5..0cefc24533 100644
--- a/src/opers.c
+++ b/src/opers.c
@@ -44,6 +44,9 @@
 #include <pthread.h>
 #endif
 
+#include <stdio.h>
+
+
 /****************************************************************************
 **
 *V  TRY_NEXT_METHOD . . . . . . . . . . . . . . . . .  'TRY_NEXT_METHOD' flag
diff --git a/src/plist.h b/src/plist.h
index c2f0ef2ff5..f5bc202a65 100644
--- a/src/plist.h
+++ b/src/plist.h
@@ -28,6 +28,8 @@
 
 #include "objects.h"
 
+#include <string.h>
+
 /****************************************************************************
 **
 *F  NEW_PLIST(<type>,<plen>)  . . . . . . . . . . . allocate a new plain list
diff --git a/src/precord.c b/src/precord.c
index 1bcb289540..932fc9da95 100644
--- a/src/precord.c
+++ b/src/precord.c
@@ -47,6 +47,8 @@
 #include "hpc/traverse.h"
 #endif
 
+#include <stdlib.h>
+
 /****************************************************************************
 **
 *F * * * * * * * * * standard functions for plain records * * * * * * * * * *
diff --git a/src/profile.c b/src/profile.c
index d8385dc3fb..6c00d08b1b 100644
--- a/src/profile.c
+++ b/src/profile.c
@@ -32,6 +32,7 @@
 
 #include "hpc/thread.h"
 
+#include <stdio.h>
 #include <sys/time.h>                   // for gettimeofday
 #include <sys/types.h>
 #include <unistd.h>
diff --git a/src/saveload.c b/src/saveload.c
index 7412958354..5ba7154abb 100644
--- a/src/saveload.c
+++ b/src/saveload.c
@@ -30,6 +30,7 @@
 #include "sysfiles.h"
 #include "sysopt.h"
 
+#include <stdio.h>
 #include <unistd.h>
 
 
diff --git a/src/streams.c b/src/streams.c
index 8794f7534c..ad9f41633d 100644
--- a/src/streams.c
+++ b/src/streams.c
@@ -40,6 +40,8 @@
 
 #include <dirent.h>
 #include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
 #include <time.h>
 #include <unistd.h>
 
diff --git a/src/stringobj.h b/src/stringobj.h
index 62a1b2ac55..68a4ecc93d 100644
--- a/src/stringobj.h
+++ b/src/stringobj.h
@@ -24,6 +24,8 @@
 
 #include "objects.h"
 
+#include <string.h>
+
 
 /****************************************************************************
 **
diff --git a/src/sysfiles.c b/src/sysfiles.c
index b96308b928..46427639d0 100644
--- a/src/sysfiles.c
+++ b/src/sysfiles.c
@@ -30,16 +30,15 @@
 #include "sysenv.h"
 #include "sysopt.h"
 #include "sysstr.h"
+#include "system.h"
 
 #include "hpc/thread.h"
 
-#ifdef HAVE_LIBREADLINE
-#include <readline/readline.h>
-#endif
-
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include <termios.h>
 #include <time.h>
 #include <unistd.h>
@@ -69,6 +68,10 @@ typedef void sig_handler_t ( int );
 #include <process.h>
 #endif
 
+#ifdef HAVE_LIBREADLINE
+#include <readline/readline.h>
+#endif
+
 #include <zlib.h>
 
 
diff --git a/src/sysfiles.h b/src/sysfiles.h
index 3352db0202..86f938f2e2 100644
--- a/src/sysfiles.h
+++ b/src/sysfiles.h
@@ -16,6 +16,8 @@
 
 #include "system.h"
 
+#include <stddef.h>
+
 
 /****************************************************************************
 **
diff --git a/src/sysjmp.h b/src/sysjmp.h
index 37b923913a..50e016a3ae 100644
--- a/src/sysjmp.h
+++ b/src/sysjmp.h
@@ -14,6 +14,7 @@
 
 #include "system.h"
 
+#include <setjmp.h>
 
 /****************************************************************************
 **
diff --git a/src/sysmem.c b/src/sysmem.c
index c4523aa612..9e67f8ace4 100644
--- a/src/sysmem.c
+++ b/src/sysmem.c
@@ -23,6 +23,9 @@
 #include <fcntl.h>
 #endif
 
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
 #ifdef HAVE_MADVISE
diff --git a/src/sysroots.c b/src/sysroots.c
index b4d0a7da53..e47742d4ec 100644
--- a/src/sysroots.c
+++ b/src/sysroots.c
@@ -17,6 +17,8 @@
 #include "sysfiles.h"
 #include "sysstr.h"
 
+#include <stdlib.h>
+
 
 /****************************************************************************
 **
diff --git a/src/sysroots.h b/src/sysroots.h
index c3b18be8ef..ae7341ce94 100644
--- a/src/sysroots.h
+++ b/src/sysroots.h
@@ -14,6 +14,8 @@
 
 #include "common.h"
 
+#include <stddef.h>
+
 
 /****************************************************************************
 **
diff --git a/src/system.c b/src/system.c
index 2657bc10ec..29ce9cf23e 100644
--- a/src/system.c
+++ b/src/system.c
@@ -37,6 +37,8 @@
 #include <assert.h>
 #include <fcntl.h>
 #include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include <time.h>
 #include <unistd.h>
 
diff --git a/src/systime.c b/src/systime.c
index a99bab3d7d..457b39f529 100644
--- a/src/systime.c
+++ b/src/systime.c
@@ -13,6 +13,7 @@
 
 #include "system.h"
 
+#include <stddef.h>
 #include <sys/time.h>
 #include <sys/types.h>
 
diff --git a/src/trans.cc b/src/trans.cc
index f230c18b77..d04106b480 100644
--- a/src/trans.cc
+++ b/src/trans.cc
@@ -64,6 +64,8 @@ extern "C" {
 #include "plist.h"
 #include "saveload.h"
 
+#include <stdio.h>
+
 } // extern "C"
 
 #include "permutat_intern.hh"
diff --git a/src/vars.c b/src/vars.c
index a39b7dc7e6..6bfa166e8f 100644
--- a/src/vars.c
+++ b/src/vars.c
@@ -43,6 +43,9 @@
 #include "hpc/guards.h"
 #endif
 
+#include <stdio.h>
+
+
 /****************************************************************************
 **
 *V  CurrLVars   . . . . . . . . . . . . . . . . . . . . . local variables bag
diff --git a/tst/testkernel/dstruct.c b/tst/testkernel/dstruct.c
index 6087fce81a..d219dd3b1b 100644
--- a/tst/testkernel/dstruct.c
+++ b/tst/testkernel/dstruct.c
@@ -4,6 +4,8 @@
 
 #include <libgap-api.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
 static int int_cmp(int a, int b)
 {
diff --git a/tst/testlibgap/api.c b/tst/testlibgap/api.c
index 6b5598eb0f..53093eb65e 100644
--- a/tst/testlibgap/api.c
+++ b/tst/testlibgap/api.c
@@ -11,9 +11,9 @@
  */
 
 #include "common.h"
+#include "intobj.h"
 
-#include <intobj.h>
-
+#include <string.h>
 
 void records(void)
 {
diff --git a/tst/testlibgap/wsload.c b/tst/testlibgap/wsload.c
index 994ff50062..21af6d6049 100644
--- a/tst/testlibgap/wsload.c
+++ b/tst/testlibgap/wsload.c
@@ -3,6 +3,9 @@
  * Also shows how to directly pass command line arguments to libgap.
  */
 #include "common.h"
+
+#include <string.h>
+
 int main(int argc, char ** argv)
 {
     char *args[50];