diff --git a/cue/testdata/comprehensions/nested2.txtar b/cue/testdata/comprehensions/nested2.txtar
new file mode 100644
index 0000000..df3fc90
--- /dev/null
+++ b/cue/testdata/comprehensions/nested2.txtar
@@ -0,0 +1,92 @@
+-- in.cue --
+given: {
+	INC: USD: 2.0
+	USD: GBP: 3.0
+}
+hydrated: {
+	for k,v in given {
+		for k1,r in v {
+			"\(k)": "\(k)":  1.0
+			"\(k1)": "\(k1)": 1.0
+			"\(k)": "\(k1)": r
+			"\(k1)": "\(k)": number
+		}
+	}
+}
+
+foo: {
+    a: 10
+    if a < 20 {
+        if a < 50 {
+            b: 20
+        }
+    }
+}
+-- out/eval --
+(struct){
+  given: (struct){
+    INC: (struct){
+      USD: (float){ 2.0 }
+    }
+    USD: (struct){
+      GBP: (float){ 3.0 }
+    }
+  }
+  hydrated: (struct){
+    INC: (struct){
+      INC: (float){ 1.0 }
+      USD: (float){ 2.0 }
+    }
+    USD: (struct){
+      USD: (float){ 1.0 }
+      INC: (number){ number }
+      GBP: (float){ 3.0 }
+    }
+    GBP: (struct){
+      GBP: (float){ 1.0 }
+      USD: (number){ number }
+    }
+  }
+  foo: (struct){
+    a: (int){ 10 }
+    b: (int){ 20 }
+  }
+}
+-- out/compile --
+--- in.cue
+{
+  given: {
+    INC: {
+      USD: 2.0
+    }
+    USD: {
+      GBP: 3.0
+    }
+  }
+  hydrated: {
+    for k, v in 〈1;given〉 {
+      for k1, r in 〈1;v〉 {
+        "\(〈3;k〉)": {
+          "\(〈4;k〉)": 1.0
+        }
+        "\(〈1;k1〉)": {
+          "\(〈2;k1〉)": 1.0
+        }
+        "\(〈3;k〉)": {
+          "\(〈2;k1〉)": 〈2;r〉
+        }
+        "\(〈1;k1〉)": {
+          "\(〈4;k〉)": number
+        }
+      }
+    }
+  }
+  foo: {
+    a: 10
+    if (〈0;a〉 < 20) {
+      if (〈1;a〉 < 50) {
+        b: 20
+      }
+    }
+  }
+}
diff --git a/internal/core/eval/eval.go b/internal/core/eval/eval.go
index 8b58c7e..3298f7d 100644
--- a/internal/core/eval/eval.go
+++ b/internal/core/eval/eval.go
@@ -1482,11 +1482,11 @@
 		return true
 	}
 
-	if n.ifClauses, progress = n.injectEmbedded(n.ifClauses); progress {
+	if progress = n.injectEmbedded(&(n.ifClauses)); progress {
 		return true
 	}
 
-	if n.forClauses, progress = n.injectEmbedded(n.forClauses); progress {
+	if progress = n.injectEmbedded(&(n.forClauses)); progress {
 		return true
 	}
 
@@ -1542,7 +1542,7 @@
 // injectEmbedded evaluates and inserts embeddings. It first evaluates all
 // embeddings before inserting the results to ensure that the order of
 // evaluation does not matter.
-func (n *nodeContext) injectEmbedded(all []envYield) (a []envYield, progress bool) {
+func (n *nodeContext) injectEmbedded(all *[]envYield) (progress bool) {
 	ctx := n.ctx
 	type envStruct struct {
 		env *adt.Environment
@@ -1554,12 +1554,13 @@
 	}
 
 	k := 0
-	for _, d := range all {
+	for i := 0; i < len(*all); i++ {
+		d := (*all)[i]
 		sa = sa[:0]
 
 		if err := ctx.Yield(d.env, d.yield, f); err != nil {
 			if err.IsIncomplete() {
-				all[k] = d
+				(*all)[k] = d
 				k++
 			} else {
 				// continue to collect other errors.
@@ -1573,7 +1574,8 @@
 		}
 	}
 
-	return all[:k], k < len(all)
+	*all = (*all)[:k]
+	return k < len(*all)
 }
 
 // addLists