diff --git a/src/Sema.zig b/src/Sema.zig
index 934fa4064b0c22feb80c4ab46a493be0d07c1f1d..07e71c4bff3c368c37e4a4fe5f701facc854798b 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -7058,6 +7058,7 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError
                 sema.air_extra.appendSliceAssumeCapacity(prev_then_body);
                 sema.air_extra.appendSliceAssumeCapacity(cond_body);
             }
+            gpa.free(prev_then_body);
             prev_then_body = case_block.instructions.toOwnedSlice(gpa);
             prev_cond_br = new_cond_br;
         }