diff --git a/src/mesa/program/prog_parameter.h b/src/mesa/program/prog_parameter.h
index 1a5ed343937..4c2773a62c3 100644
--- a/src/mesa/program/prog_parameter.h
+++ b/src/mesa/program/prog_parameter.h
@@ -53,7 +53,7 @@
 typedef union gl_constant_value
 {
    GLfloat f;
-   GLboolean b;
+   GLint b;
    GLint i;
    GLuint u;
 } gl_constant_value;