diff --git a/src/arch/x86/isa/formats/error.isa b/src/arch/x86/isa/formats/error.isa
index 8ac2ea44d..e85eff762 100644
--- a/src/arch/x86/isa/formats/error.isa
+++ b/src/arch/x86/isa/formats/error.isa
@@ -64,7 +64,7 @@
 
 def template ErrorDecode {{
     {
-        panic("X86 decoder internal error: '%%s' %%s",
+        panic("X86 decoder internal error: '%s' %s",
                 %(message)s, machInst);
     }
 }};