diff --git a/configure.ac b/configure.ac
index 8ca43e3e..aded39d1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -341,6 +341,7 @@ esac
 )
 
 LIBINT_HARD_MAX_AM=12
+AC_DEFINE_UNQUOTED(LIBINT_HARD_MAX_AM,$LIBINT_HARD_MAX_AM)
 LIBINT_MAX_AM=4
 AC_ARG_WITH(max-am,
 AS_HELP_STRING([--with-max-am=N],[Support Gaussians of angular momentum up to N. Can specify values for each derivative levels as a list N0,N1,N2...]),
diff --git a/include/libint2/config.h.in b/include/libint2/config.h.in
index bd42b26e..8c807f5f 100644
--- a/include/libint2/config.h.in
+++ b/include/libint2/config.h.in
@@ -47,6 +47,9 @@
 /* Prefix for all names in API */
 #undef LIBINT_API_PREFIX
 
+/* Max AM supported by Libint *in principle* */
+#undef LIBINT_HARD_MAX_AM
+
 /* Max AM (same for all derivatives; if not defined see LIBINT_MAX_AM_LIST) */
 #undef LIBINT_MAX_AM
 
diff --git a/include/libint2/solidharmonics.h b/include/libint2/solidharmonics.h
index d09705f6..166bc23e 100644
--- a/include/libint2/solidharmonics.h
+++ b/include/libint2/solidharmonics.h
@@ -83,7 +83,8 @@ class SolidHarmonicsCoefficients {
   static const SolidHarmonicsCoefficients& instance(unsigned int l) {
     static std::vector<SolidHarmonicsCoefficients> shg_coefs(
         SolidHarmonicsCoefficients::CtorHelperIter(0),
-        SolidHarmonicsCoefficients::CtorHelperIter(13));
+        SolidHarmonicsCoefficients::CtorHelperIter(LIBINT_HARD_MAX_AM + 1));
+    assert(l < shg_coefs.size());
     return shg_coefs[l];
   }