diff --git a/src/gallium/auxiliary/util/u_screen.c b/src/gallium/auxiliary/util/u_screen.c
index 048749e3099..b6bb1fdd823 100644
--- a/src/gallium/auxiliary/util/u_screen.c
+++ b/src/gallium/auxiliary/util/u_screen.c
@@ -35,6 +35,8 @@ int
 u_pipe_screen_get_param_defaults(struct pipe_screen *pscreen,
                                  enum pipe_cap param)
 {
+   assert(param < PIPE_CAP_LAST);
+
    /* Let's keep these sorted by position in p_defines.h. */
    switch (param) {
    case PIPE_CAP_NPOT_TEXTURES:
diff --git a/src/gallium/drivers/nouveau/nv50/nv50_screen.c b/src/gallium/drivers/nouveau/nv50/nv50_screen.c
index 6be9dde3039..8b9c58797b7 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_screen.c
+++ b/src/gallium/drivers/nouveau/nv50/nv50_screen.c
@@ -91,6 +91,7 @@ nv50_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
 {
    const uint16_t class_3d = nouveau_screen(pscreen)->class_3d;
    struct nouveau_device *dev = nouveau_screen(pscreen)->device;
+   static bool debug_cap_printed[PIPE_CAP_LAST] = {};
 
    switch (param) {
    /* non-boolean caps */
@@ -389,7 +390,10 @@ nv50_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
       return 0;
 
    default:
-      debug_printf("%s: unhandled cap %d\n", __func__, param);
+      if (!debug_cap_printed[param]) {
+         debug_printf("%s: unhandled cap %d\n", __func__, param);
+         debug_cap_printed[param] = true;
+      }
       /* fallthrough */
    /* caps where we want the default value */
    case PIPE_CAP_DMABUF:
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
index 265cc7ecee3..95d8a29d31b 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
@@ -109,6 +109,7 @@ nvc0_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    const uint16_t class_3d = nouveau_screen(pscreen)->class_3d;
    const struct nouveau_screen *screen = nouveau_screen(pscreen);
    struct nouveau_device *dev = screen->device;
+   static bool debug_cap_printed[PIPE_CAP_LAST] = {};
 
    switch (param) {
    /* non-boolean caps */
@@ -431,7 +432,10 @@ nvc0_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
       return 0;
 
    default:
-      debug_printf("%s: unhandled cap %d\n", __func__, param);
+      if (!debug_cap_printed[param]) {
+         debug_printf("%s: unhandled cap %d\n", __func__, param);
+         debug_cap_printed[param] = true;
+      }
       /* fallthrough */
    /* caps where we want the default value */
    case PIPE_CAP_DMABUF:
diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index 3b984b716ca..db595c73728 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -977,6 +977,9 @@ enum pipe_cap
    PIPE_CAP_SHADER_ATOMIC_INT64,
    PIPE_CAP_DEVICE_PROTECTED_CONTENT,
    PIPE_CAP_PREFER_REAL_BUFFER_IN_CONSTBUF0,
+
+   PIPE_CAP_LAST,
+   /* XXX do not add caps after PIPE_CAP_LAST! */
 };
 
 /**