diff --git a/src/prism.c b/src/prism.c
index c5f5744f58..4dd519962a 100644
--- a/src/prism.c
+++ b/src/prism.c
@@ -17393,6 +17393,14 @@ parse_pattern_primitive(pm_parser_t *parser, pm_constant_id_list_t *captures, pm
             // If we found a label, we need to immediately return to the caller.
             if (pm_symbol_node_label_p(node)) return node;
 
+            // Call nodes (arithmetic operations) are not allowed in patterns
+            if (PM_NODE_TYPE(node) == PM_CALL_NODE) {
+                pm_parser_err_node(parser, node, diag_id);
+                pm_missing_node_t *missing_node = pm_missing_node_create(parser, node->location.start, node->location.end);
+                pm_node_destroy(parser, node);
+                return (pm_node_t *) missing_node;
+            }
+
             // Now that we have a primitive, we need to check if it's part of a range.
             if (accept2(parser, PM_TOKEN_DOT_DOT, PM_TOKEN_DOT_DOT_DOT)) {
                 pm_token_t operator = parser->previous;
diff --git a/test/prism/errors/pattern_arithmetic_expressions.txt b/test/prism/errors/pattern_arithmetic_expressions.txt
new file mode 100644
index 0000000000..cfb3650531
--- /dev/null
+++ b/test/prism/errors/pattern_arithmetic_expressions.txt
@@ -0,0 +1,3 @@
+case 1; in -1**2; end
+           ^~~~~ expected a pattern expression after the `in` keyword
+