diff --git a/src/prism.c b/src/prism.c
index efe21c5e7e..2e2d6bcbd4 100644
--- a/src/prism.c
+++ b/src/prism.c
@@ -21621,7 +21621,7 @@ parse_expression(pm_parser_t *parser, pm_binding_power_t binding_power, bool acc
                     return node;
                 }
                 break;
-            case PM_CALL_NODE:
+            case PM_CALL_NODE: {
                 // A do-block can attach to a command-style call
                 // produced by infix operators (e.g., dot-calls like
                 // `obj.method args do end`).
@@ -21635,7 +21635,22 @@ parse_expression(pm_parser_t *parser, pm_binding_power_t binding_power, bool acc
                 if (PM_NODE_FLAG_P(node, PM_CALL_NODE_FLAGS_IMPLICIT_ARRAY) && pm_binding_powers[parser->current.type].left > PM_BINDING_POWER_MODIFIER) {
                     return node;
                 }
+
+                // Command-style calls (calls with arguments but without
+                // parentheses) only accept composition (and/or) and modifier
+                // (if/unless/etc.) operators. We need to exclude operator calls
+                // (e.g., a + b) which also satisfy pm_call_node_command_p but
+                // are not commands.
+                const pm_call_node_t *cast = (const pm_call_node_t *) node;
+                if (
+                    (pm_binding_powers[parser->current.type].left > PM_BINDING_POWER_COMPOSITION) &&
+                    (cast->receiver == NULL || cast->call_operator_loc.length > 0) &&
+                    pm_call_node_command_p(cast)
+                ) {
+                    return node;
+                }
                 break;
+            }
             case PM_RESCUE_MODIFIER_NODE:
                 // A rescue modifier whose handler is a one-liner pattern match
                 // (=> or in) produces a statement. That means it cannot be
diff --git a/test/prism/errors/command_call_in_2.txt b/test/prism/errors/command_call_in_2.txt
new file mode 100644
index 0000000000..6676b1acba
--- /dev/null
+++ b/test/prism/errors/command_call_in_2.txt
@@ -0,0 +1,4 @@
+a.b x in pattern
+      ^~ unexpected 'in', expecting end-of-input
+      ^~ unexpected 'in', ignoring it
+
diff --git a/test/prism/errors/command_call_in_3.txt b/test/prism/errors/command_call_in_3.txt
new file mode 100644
index 0000000000..6fe026d7d3
--- /dev/null
+++ b/test/prism/errors/command_call_in_3.txt
@@ -0,0 +1,4 @@
+a.b x: in pattern
+       ^~ unexpected 'in', expecting end-of-input
+       ^~ unexpected 'in', ignoring it
+
diff --git a/test/prism/errors/command_call_in_4.txt b/test/prism/errors/command_call_in_4.txt
new file mode 100644
index 0000000000..045afe6498
--- /dev/null
+++ b/test/prism/errors/command_call_in_4.txt
@@ -0,0 +1,4 @@
+a.b &x in pattern
+       ^~ unexpected 'in', expecting end-of-input
+       ^~ unexpected 'in', ignoring it
+
diff --git a/test/prism/errors/command_call_in_5.txt b/test/prism/errors/command_call_in_5.txt
new file mode 100644
index 0000000000..be07287f81
--- /dev/null
+++ b/test/prism/errors/command_call_in_5.txt
@@ -0,0 +1,4 @@
+a.b *x => pattern
+       ^~ unexpected '=>', expecting end-of-input
+       ^~ unexpected '=>', ignoring it
+
diff --git a/test/prism/errors/command_call_in_6.txt b/test/prism/errors/command_call_in_6.txt
new file mode 100644
index 0000000000..470f323872
--- /dev/null
+++ b/test/prism/errors/command_call_in_6.txt
@@ -0,0 +1,4 @@
+a.b x: => pattern
+       ^~ unexpected '=>', expecting end-of-input
+       ^~ unexpected '=>', ignoring it
+
diff --git a/test/prism/errors/command_call_in_7.txt b/test/prism/errors/command_call_in_7.txt
new file mode 100644
index 0000000000..a8bea912b5
--- /dev/null
+++ b/test/prism/errors/command_call_in_7.txt
@@ -0,0 +1,4 @@
+a.b &x => pattern
+       ^~ unexpected '=>', expecting end-of-input
+       ^~ unexpected '=>', ignoring it
+
diff --git a/test/prism/errors_test.rb b/test/prism/errors_test.rb
index 898f4afb45..c3362eaaf5 100644
--- a/test/prism/errors_test.rb
+++ b/test/prism/errors_test.rb
@@ -60,10 +60,6 @@ def test_unterminated_empty_string_closing
       assert_nil statement.closing
     end
 
-    def test_invalid_message_name
-      assert_equal :"", Prism.parse_statement("+.@foo,+=foo").write_name
-    end
-
     def test_regexp_encoding_option_mismatch_error
       # UTF-8 char with ASCII-8BIT modifier
       result = Prism.parse('/Ȃ/n')