diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 86e12c522c411899a2593a0846c72a1a21d872c8..9b8eeee66b3eb13dfbb5c59d8ec7580d33cb4f1f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2003-08-04  Janis Johnson  <janis187@us.ibm.com>
+
+	PR target/11739
+	* gcc.misc-tests/i386-prefetch.exp: Use -march=i386 when specifying
+	a value for -mtune.
+
 2003-08-04  Roger Sayle  <roger@eyesopen.com>
 
 	PR middle-end/11771
diff --git a/gcc/testsuite/gcc.misc-tests/i386-prefetch.exp b/gcc/testsuite/gcc.misc-tests/i386-prefetch.exp
index f452038929e388e49a64c5bbadb27ad2beb81d33..2290478902d69eeb0e82a0ba1bafdc9b0c32afd8 100644
--- a/gcc/testsuite/gcc.misc-tests/i386-prefetch.exp
+++ b/gcc/testsuite/gcc.misc-tests/i386-prefetch.exp
@@ -16,7 +16,9 @@
 
 # Test that the correct data prefetch instructions (SSE or 3DNow! variant,
 # or none) are used for various i386 cpu-type and instruction set
-# extension options for __builtin_prefetch.
+# extension options for __builtin_prefetch.  When using -mtune, specify
+# the minimum supported architecture in case the compiler was configured
+# with a different default.
 
 # Failure reports do not include the compile option that was used; that
 # information can be seen in the compile line in the log file.
@@ -24,14 +26,14 @@
 # Do not generate prefetch instructions for the following options.
 
 set PREFETCH_NONE [list \
-	{ -mtune=i386 } \
-	{ -mtune=i486 } \
-	{ -mtune=i586 } \
-	{ -mtune=i686 } \
-	{ -mtune=pentium2 } \
-	{ -mtune=k6 } \
-	{ -mtune=k6-2 } \
-	{ -mtune=k6-3 } \
+	{ -march=i386 -mtune=i386 } \
+	{ -march=i386 -mtune=i486 } \
+	{ -march=i386 -mtune=i586 } \
+	{ -march=i386 -mtune=i686 } \
+	{ -march=i386 -mtune=pentium2 } \
+	{ -march=i386 -mtune=k6 } \
+	{ -march=i386 -mtune=k6-2 } \
+	{ -march=i386 -mtune=k6-3 } \
 	{ -march=i386 } \
 	{ -march=i486 } \
 	{ -march=i586 } \
@@ -44,10 +46,10 @@ set PREFETCH_NONE [list \
 # instructions as nops.
 
 set PREFETCH_SSE [list \
-	{ -mtune=pentium3 } \
-	{ -mtune=pentium4 } \
-	{ -mtune=athlon } \
-	{ -mtune=athlon-4 } \
+	{ -march=i386 -mtune=pentium3 } \
+	{ -march=i386 -mtune=pentium4 } \
+	{ -march=i386 -mtune=athlon } \
+	{ -march=i386 -mtune=athlon-4 } \
 	{ -march=pentium3 } \
 	{ -march=pentium4 } ]