diff --git a/opengl/libagl/state.cpp b/opengl/libagl/state.cpp
index 1d5def5..8bb7e83 100644
--- a/opengl/libagl/state.cpp
+++ b/opengl/libagl/state.cpp
@@ -181,7 +181,7 @@
     case GL_FOG:
     case GL_DEPTH_TEST:
         ogles_invalidate_perspective(c);
-        // fall-through...
+        [[fallthrough]];
     case GL_BLEND:
     case GL_SCISSOR_TEST:
     case GL_ALPHA_TEST:
diff --git a/opengl/libagl/texture.cpp b/opengl/libagl/texture.cpp
index aae8e05..4c5f3e9 100644
--- a/opengl/libagl/texture.cpp
+++ b/opengl/libagl/texture.cpp
@@ -401,14 +401,14 @@
     switch (format) {
     case GL_PALETTE4_RGB8_OES:
         indexBits = 4;
-        /* FALLTHROUGH */
+        [[fallthrough]];
     case GL_PALETTE8_RGB8_OES:
         entrySize = 3;
         break;
 
     case GL_PALETTE4_RGBA8_OES:
         indexBits = 4;
-        /* FALLTHROUGH */
+        [[fallthrough]];
     case GL_PALETTE8_RGBA8_OES:
         entrySize = 4;
         break;
@@ -417,7 +417,7 @@
     case GL_PALETTE4_RGBA4_OES:
     case GL_PALETTE4_RGB5_A1_OES:
         indexBits = 4;
-        /* FALLTHROUGH */
+        [[fallthrough]];
     case GL_PALETTE8_R5_G6_B5_OES:
     case GL_PALETTE8_RGBA4_OES:
     case GL_PALETTE8_RGB5_A1_OES:
@@ -446,14 +446,14 @@
     switch (format) {
     case GL_PALETTE4_RGB8_OES:
         indexBits = 4;
-        /* FALLTHROUGH */
+        [[fallthrough]];
     case GL_PALETTE8_RGB8_OES:
         entrySize = 3;
         break;
 
     case GL_PALETTE4_RGBA8_OES:
         indexBits = 4;
-        /* FALLTHROUGH */
+        [[fallthrough]];
     case GL_PALETTE8_RGBA8_OES:
         entrySize = 4;
         break;
@@ -462,7 +462,7 @@
     case GL_PALETTE4_RGBA4_OES:
     case GL_PALETTE4_RGB5_A1_OES:
         indexBits = 4;
-        /* FALLTHROUGH */
+        [[fallthrough]];
     case GL_PALETTE8_R5_G6_B5_OES:
     case GL_PALETTE8_RGBA4_OES:
     case GL_PALETTE8_RGB5_A1_OES: