diff --git a/configure.ac b/configure.ac
index a45af9c2c..c439ae6e1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -188,15 +188,15 @@ AS_CASE([$ENABLED_FIPS],
     ])
 
 case "$FIPS_VERSION" in
-none) if test -s wolfcrypt/src/fips.c || test -s ctaocrypt/src/fips.c; then
+none) if test -s $srcdir/wolfcrypt/src/fips.c || test -s $srcdir/ctaocrypt/src/fips.c; then
         AC_MSG_ERROR([FIPS source tree is incompatible with non-FIPS build (requires --enable-fips)])
     fi
     ;;
-v1) if ! test -s ctaocrypt/src/fips.c; then
+v1) if ! test -s $srcdir/ctaocrypt/src/fips.c; then
         AC_MSG_ERROR([non-FIPS-v1 source tree is incompatible with --enable-fips=$enableval])
     fi
     ;;
-*) if ! test -s wolfcrypt/src/fips.c; then
+*) if ! test -s $srcdir/wolfcrypt/src/fips.c; then
         AC_MSG_ERROR([non-FIPS source tree is incompatible with --enable-fips=$enableval])
    fi
    ;;