diff --git a/bin/sh/eval.c b/bin/sh/eval.c
index e00a94a82b85..82e74b88bf09 100644
--- a/bin/sh/eval.c
+++ b/bin/sh/eval.c
@@ -594,7 +594,7 @@ evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
 	char *lastarg;
 	int realstatus;
 	int do_clearcmdentry;
-#if __GNUC__
+#ifdef __GNUC__
 	/* Avoid longjmp clobbering */
 	(void) &argv;
 	(void) &argc;
diff --git a/bin/sh/parser.c b/bin/sh/parser.c
index eb7501e04ef1..d17dc1a11485 100644
--- a/bin/sh/parser.c
+++ b/bin/sh/parser.c
@@ -898,7 +898,7 @@ readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs)
 	int oldstyle;
 	char const *prevsyntax;	/* syntax before arithmetic */
 	int synentry;
-#if __GNUC__
+#ifdef __GNUC__
 	/* Avoid longjmp clobbering */
 	(void) &out;
 	(void) &quotef;
@@ -1323,7 +1323,7 @@ parsebackq: {
 	struct jmploc *volatile savehandler;
 	int savelen;
 	int saveprompt;
-#if __GNUC__
+#ifdef __GNUC__
 	/* Avoid longjmp clobbering */
 	(void) &saveprompt;
 #endif
diff --git a/bin/sh/var.c b/bin/sh/var.c
index 6f7c578499ec..a12a568a9b5c 100644
--- a/bin/sh/var.c
+++ b/bin/sh/var.c
@@ -195,7 +195,7 @@ setvarsafe(char *name, char *val, int flags)
 	struct jmploc jmploc;
 	struct jmploc *volatile savehandler = handler;
 	int err = 0;
-#if __GNUC__
+#ifdef __GNUC__
 	/* Avoid longjmp clobbering */
 	(void) &err;
 #endif