diff --git a/src/check_asm.cpp b/src/check_asm.cpp
index 19d35bf58..3f7bfd9c9 100644
--- a/src/check_asm.cpp
+++ b/src/check_asm.cpp
@@ -843,6 +843,11 @@ gb_internal bool check_register(AsmCtx *asm_ctx, Operand *operand, AstAsmRegiste
 
 		u16 width_in_bits = asm_ctx->reg_size(r);
 		switch (width_in_bits) {
+		case 0:
+			// a register whose class the width table cannot describe, `%rip` being the only one.
+			// anchored on the name rather than the operand, which clobbers and pins do not have
+			error(asm_reg->name, "Asm registers with no operand width are not supported: %%%.*s", LIT(name));
+			return false;
 		case 8:
 			operand->type = t_u8;
 			break;
@@ -856,7 +861,7 @@ gb_internal bool check_register(AsmCtx *asm_ctx, Operand *operand, AstAsmRegiste
 			operand->type = t_u64;
 			break;
 		case 80:
-			error(operand->expr, "80-bit width asm registers are not supported");
+			error(asm_reg->name, "80-bit width asm registers are not supported");
 			return false;
 		case 128:
 			operand->type = alloc_type_simd_vector(4, t_f32);
diff --git a/tests/issues/run.bat b/tests/issues/run.bat
index 9d83a6c05..d31751a87 100644
--- a/tests/issues/run.bat
+++ b/tests/issues/run.bat
@@ -47,6 +47,7 @@ set COMMON=-define:ODIN_TEST_FANCY=false -file -vet -strict-style -ignore-unused
 ..\..\..\odin check ..\test_issue_ellipsis_type_call.odin -no-entry-point %COMMON% 2>&1 | find /c "Error:" | findstr /x "10" || exit /b
 ..\..\..\odin check ..\test_issue_foreign_redeclaration.odin -no-entry-point %COMMON% || exit /b
 ..\..\..\odin check ..\test_issue_foreign_redeclaration_mismatch.odin -no-entry-point %COMMON% 2>&1 | find /c "Error:" | findstr /x "1" || exit /b
+..\..\..\odin check ..\test_issue_asm_rip_register.odin -no-entry-point %COMMON% 2>&1 | find /c "Error:" | findstr /x "6" || exit /b
 ..\..\..\odin check ..\test_issue_asm_template_as_value.odin -no-entry-point %COMMON% 2>&1 | find /c "Error:" | findstr /x "10" || exit /b
 ..\..\..\odin build ..\test_issue_7037.odin %COMMON% -o:none  || exit /b
 ..\..\..\odin build ..\test_issue_7188.odin %COMMON%  || exit /b
diff --git a/tests/issues/run.sh b/tests/issues/run.sh
index 8794c95df..3e7d4428d 100755
--- a/tests/issues/run.sh
+++ b/tests/issues/run.sh
@@ -122,6 +122,12 @@ fi
 
 # `asm` templates are amd64-only, so this file is empty on every other architecture
 if [[ "$(uname -m)" == "x86_64" || "$(uname -m)" == "amd64" ]]; then
+	if [[ $($ODIN check ../test_issue_asm_rip_register.odin -no-entry-point $COMMON_CHECK 2>&1 >/dev/null | grep -c "Error:") -eq 6 ]]; then
+  	echo "SUCCESSFUL 1/1"
+	else
+		echo "SUCCESSFUL 0/1"
+	  exit 1
+  fi
 	if [[ $($ODIN check ../test_issue_asm_template_as_value.odin -no-entry-point $COMMON_CHECK 2>&1 >/dev/null | grep -c "Error:") -eq 10 ]]; then
 		echo "SUCCESSFUL 1/1"
 	else
diff --git a/tests/issues/test_issue_asm_rip_register.odin b/tests/issues/test_issue_asm_rip_register.odin
new file mode 100644
index 000000000..8b9784790
--- /dev/null
+++ b/tests/issues/test_issue_asm_rip_register.odin
@@ -0,0 +1,15 @@
+#+build amd64
+// `%rip` is in the amd64 register table, but its class carries no width, so the checker's width
+// switch reached its `GB_PANIC` default arm and aborted with SIGILL instead of diagnosing. Every
+// position that can name a register reached it, including `[%rip + disp]`.
+package test_issues
+
+rip_src  :: asm() -> (v: u64) { mov v, %rip; }
+rip_dst  :: asm(x: u64) { mov %rip, x; }
+rip_mem  :: asm() { mov %rax, [%rip + 8]; }
+rip_clob :: asm() [#clobber %rip] { nop; }
+rip_in   :: asm(x: u64) [x = %rip] { nop; }
+rip_out  :: asm() -> (r: u64) [r = %rip] { nop; }
+
+// the nearest special-purpose register that does carry a class has to keep checking cleanly
+rsp_ok :: asm() -> (v: u64) { mov v, %rsp; }