diff --git a/lib/Conversion/SCFToCalyx/SCFToCalyx.cpp b/lib/Conversion/SCFToCalyx/SCFToCalyx.cpp
index 7c9bb9561a7e..9163a00cbee0 100644
--- a/lib/Conversion/SCFToCalyx/SCFToCalyx.cpp
+++ b/lib/Conversion/SCFToCalyx/SCFToCalyx.cpp
@@ -29,8 +29,11 @@
 #include "mlir/Pass/Pass.h"
 #include "mlir/Support/LogicalResult.h"
 #include "mlir/Transforms/GreedyPatternRewriteDriver.h"
+#include "llvm/ADT/APInt.h"
 #include "llvm/ADT/TypeSwitch.h"
+#include "llvm/BinaryFormat/MsgPackReader.h"
 #include "llvm/Support/LogicalResult.h"
+#include "llvm/Support/NativeFormatting.h"
 #include "llvm/Support/raw_os_ostream.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
@@ -38,6 +41,7 @@
 #include <fstream>
 
 #include <locale>
+#include <mlir/IR/BuiltinAttributes.h>
 #include <numeric>
 #include <variant>
 
@@ -1301,10 +1305,19 @@ static LogicalResult buildAllocOp(ComponentLoweringState &componentState,
       rewriter, allocOp.getLoc(), componentState.getUniqueName("mem"),
       memtype.getElementType().getIntOrFloatBitWidth(), sizes, addrSizes);
 
+  auto componentOp = componentState.getComponentOp();
+
   // Externalize memories conditionally (only in the top-level component because
   // Calyx compiler requires it as a well-formness check).
-  memoryOp->setAttr("external",
-                    IntegerAttr::get(rewriter.getI1Type(), llvm::APInt(1, 1)));
+  if (componentOp->hasAttr("toplevel")) {
+    memoryOp->setAttr(
+        "external", IntegerAttr::get(rewriter.getI1Type(), llvm::APInt(1, 1)));
+
+  } else {
+    memoryOp->setAttr(
+        "external", IntegerAttr::get(rewriter.getI1Type(), llvm::APInt(1, 0)));
+  }
+
   componentState.registerMemoryInterface(allocOp.getResult(),
                                          calyx::MemoryInterface(memoryOp));
 
diff --git a/lib/Dialect/Calyx/Export/CalyxEmitter.cpp b/lib/Dialect/Calyx/Export/CalyxEmitter.cpp
index 18a589bd11a3..147c60bed947 100644
--- a/lib/Dialect/Calyx/Export/CalyxEmitter.cpp
+++ b/lib/Dialect/Calyx/Export/CalyxEmitter.cpp
@@ -374,6 +374,10 @@ struct Emitter {
       if (!atFormat) {
         buffer << quote() << identifier << quote() << equals() << value;
       } else {
+        // don't emit external(0)
+        if (identifier == "external" && intAttr.getValue() == 0) {
+          return "";
+        }
         buffer << addressSymbol() << identifier;
         // The only time we may omit the value is when it is a Boolean attribute
         // with value 1.
@@ -875,6 +879,7 @@ void Emitter::emitSeqMemory(SeqMemoryOp memory) {
                         "supported by the native Calyx compiler.");
     return;
   }
+
   bool isRef = !memory->hasAttr("external");
   indent();
   if (isRef)