diff --git a/src/gallium/drivers/iris/iris_context.h b/src/gallium/drivers/iris/iris_context.h
index 05bbd177488..9652f84b971 100644
--- a/src/gallium/drivers/iris/iris_context.h
+++ b/src/gallium/drivers/iris/iris_context.h
@@ -29,6 +29,7 @@
 #include "util/set.h"
 #include "util/slab.h"
 #include "util/u_debug.h"
+#include "util/macros.h"
 #include "util/u_threaded_context.h"
 #include "intel/blorp/blorp.h"
 #include "intel/dev/intel_debug.h"
@@ -206,15 +207,23 @@ enum iris_nos_dep {
  * Program cache keys for state based recompiles.
  */
 
-struct iris_base_prog_key {
-   unsigned program_string_id;
-   bool limit_trig_input_range;
-};
+/* Provide explicit padding for each member, to ensure that the compiler
+ * initializes every bit in the shader cache keys.  The keys will be compared
+ * with memcmp.
+ */
+PRAGMA_DIAGNOSTIC_PUSH
+PRAGMA_DIAGNOSTIC_ERROR(-Wpadded)
 
 /**
  * Note, we need to take care to have padding explicitly declared
  * for key since we will directly memcmp the whole struct.
  */
+struct iris_base_prog_key {
+   unsigned program_string_id;
+   bool limit_trig_input_range;
+   unsigned padding:24;
+};
+
 struct iris_vue_prog_key {
    struct iris_base_prog_key base;
 
@@ -234,6 +243,7 @@ struct iris_tcs_prog_key {
    uint8_t input_vertices;
 
    bool quads_workaround;
+   unsigned padding:16;
 
    /** A bitfield of per-patch outputs written. */
    uint32_t patch_outputs_written;
@@ -268,8 +278,11 @@ struct iris_fs_prog_key {
    bool multisample_fbo:1;
    bool force_dual_color_blend:1;
    bool coherent_fb_fetch:1;
+   unsigned padding_1:3;
 
    uint8_t color_outputs_valid;
+   uint64_t padding_2:40;
+
    uint64_t input_slots_valid;
 };
 
@@ -288,6 +301,9 @@ union iris_any_prog_key {
    struct iris_cs_prog_key cs;
 };
 
+/* Restore the pack alignment to default. */
+PRAGMA_DIAGNOSTIC_POP
+
 /** @} */
 
 struct iris_depth_stencil_alpha_state;