diff --git a/external/bsd/nvi/dist/ex/ex_read.c b/external/bsd/nvi/dist/ex/ex_read.c
index 16a905050..41061086c 100644
--- a/external/bsd/nvi/dist/ex/ex_read.c
+++ b/external/bsd/nvi/dist/ex/ex_read.c
@@ -58,6 +58,10 @@ ex_read(SCR *sp, EXCMD *cmdp)
 	int argc, rval;
 	char *p;
 
+#if defined(__minix)
+	/* Prevent complains from GCC at -O3 optimisation level. */
+	nlines = 0;
+#endif /* defined(__minix) */
 	gp = sp->gp;
 
 	/*
diff --git a/usr.bin/make/suff.c b/usr.bin/make/suff.c
index d4f0eb183..196f3efcf 100644
--- a/usr.bin/make/suff.c
+++ b/usr.bin/make/suff.c
@@ -688,6 +688,12 @@ Suff_AddTransform(char *line)
                   *t;		/* target suffix */
     LstNode 	  ln;	    	/* Node for existing transformation */
 
+#if defined(__minix)
+    /* Prevent complains from GCC at -O3 optimisation level. */
+    s = NULL;
+    t = NULL;
+#endif /* defined(__minix) */
+
     ln = Lst_Find(transforms, line, SuffGNHasNameP);
     if (ln == NULL) {
 	/*