1 files changed, 3 insertions, 0 deletions
diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatInstructions.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatInstructions.java
index 00766dbd..6591d817 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatInstructions.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatInstructions.java
@@ -6,6 +6,7 @@ import org.shedlang.compiler.backends.wasm.structure.ast.modules.WasmAlignment;
 import java.io.IOException;
 
 import static org.shedlang.compiler.backends.wasm.structure.binary.WasmBinaryFormatModules.writeLocalIndex;
+import static org.shedlang.compiler.backends.wasm.structure.binary.WasmBinaryFormatTypes.writeValueType;
 
 public class WasmBinaryFormatInstructions {
     // Corresponds to https://webassembly.github.io/spec/core/binary/instructions.html
@@ -136,6 +137,8 @@ public class WasmBinaryFormatInstructions {
     private static void writeBlockType(WasmBlockType blockType, WasmBinaryWriter writer) {
         if (blockType.resultTypes().isEmpty()) {
             writer.writeByte(0x40);
+        } else if (blockType.resultTypes().size() == 1) {
+            writeValueType(blockType.resultTypes().get(0), writer);
         } else {
             // TODO: implement this
             throw new RuntimeException("not implemented");