diff --git a/autoconf/ast_check_raii.m4 b/autoconf/ast_check_raii.m4
index e39a43d2e1..571dc1891f 100644
--- a/autoconf/ast_check_raii.m4
+++ b/autoconf/ast_check_raii.m4
@@ -33,11 +33,11 @@ AC_DEFUN([AST_CHECK_RAII], [
 			AST_C_COMPILER_FAMILY="gcc"
 		],[
 			AC_MSG_CHECKING(for clang -fblocks)
-			if test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c - 2>&1`" = ""; then
+			if test "`echo 'int main(){return ^{return 42;}();}' | ${CC} -o /dev/null -fblocks -x c - 2>&1`" = ""; then
 				AST_CLANG_BLOCKS_LIBS=""
 				AST_CLANG_BLOCKS="-Wno-unknown-warning-option -fblocks"
 				AC_MSG_RESULT(yes)
-			elif test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c -lBlocksRuntime - 2>&1`" = ""; then
+			elif test "`echo 'int main(){return ^{return 42;}();}' | ${CC} -o /dev/null -fblocks -x c -lBlocksRuntime - 2>&1`" = ""; then
 				AST_CLANG_BLOCKS_LIBS="-lBlocksRuntime"
 				AST_CLANG_BLOCKS="-fblocks"
 				AC_MSG_RESULT(yes)
diff --git a/configure b/configure
index e5b3d70cad..b7d349011f 100755
--- a/configure
+++ b/configure
@@ -9063,12 +9063,12 @@ else
 
 			{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for clang -fblocks" >&5
 $as_echo_n "checking for clang -fblocks... " >&6; }
-			if test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c - 2>&1`" = ""; then
+			if test "`echo 'int main(){return ^{return 42;}();}' | ${CC} -o /dev/null -fblocks -x c - 2>&1`" = ""; then
 				AST_CLANG_BLOCKS_LIBS=""
 				AST_CLANG_BLOCKS="-Wno-unknown-warning-option -fblocks"
 				{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 $as_echo "yes" >&6; }
-			elif test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c -lBlocksRuntime - 2>&1`" = ""; then
+			elif test "`echo 'int main(){return ^{return 42;}();}' | ${CC} -o /dev/null -fblocks -x c -lBlocksRuntime - 2>&1`" = ""; then
 				AST_CLANG_BLOCKS_LIBS="-lBlocksRuntime"
 				AST_CLANG_BLOCKS="-fblocks"
 				{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5