diff --git a/rewrite-yaml/src/main/java/org/openrewrite/yaml/CoalescePropertiesVisitor.java b/rewrite-yaml/src/main/java/org/openrewrite/yaml/CoalescePropertiesVisitor.java
index f5983ee63b..7edbe6557e 100644
--- a/rewrite-yaml/src/main/java/org/openrewrite/yaml/CoalescePropertiesVisitor.java
+++ b/rewrite-yaml/src/main/java/org/openrewrite/yaml/CoalescePropertiesVisitor.java
@@ -62,7 +62,8 @@ public Yaml.Mapping visitMapping(Yaml.Mapping mapping, P p) {
                 Yaml.Mapping valueMapping = (Yaml.Mapping) entry.getValue();
                 if (valueMapping.getEntries().size() == 1) {
                     Yaml.Mapping.Entry subEntry = valueMapping.getEntries().get(0);
-                    if (!subEntry.getPrefix().contains("#") && !isExcluded(entry, subEntry) && isApplied(entry)) {
+                    if (!subEntry.getPrefix().contains("#") && !isExcluded(entry, subEntry) && isApplied(entry)
+                            && !containsBlockScalar(subEntry.getValue())) {
                         int indentToUse = findIndent.getMostCommonIndent() > 0 ? findIndent.getMostCommonIndent() : 4;
                         doAfterVisit(new ShiftFormatLeftVisitor<>(subEntry.getValue(), indentToUse));
 
@@ -75,6 +76,28 @@ public Yaml.Mapping visitMapping(Yaml.Mapping mapping, P p) {
         }));
     }
 
+    private static boolean containsBlockScalar(Yaml.Block block) {
+        if (block instanceof Yaml.Scalar) {
+            Yaml.Scalar.Style style = ((Yaml.Scalar) block).getStyle();
+            return style == Yaml.Scalar.Style.FOLDED || style == Yaml.Scalar.Style.LITERAL;
+        }
+        if (block instanceof Yaml.Mapping) {
+            for (Yaml.Mapping.Entry e : ((Yaml.Mapping) block).getEntries()) {
+                if (containsBlockScalar(e.getValue())) {
+                    return true;
+                }
+            }
+        }
+        if (block instanceof Yaml.Sequence) {
+            for (Yaml.Sequence.Entry e : ((Yaml.Sequence) block).getEntries()) {
+                if (containsBlockScalar(e.getBlock())) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
     private boolean isExcluded(Yaml.Mapping.Entry entry, Yaml.Mapping.Entry subEntry) {
         if (exclusionMatchers.isEmpty()) {
             return false;
diff --git a/rewrite-yaml/src/main/java/org/openrewrite/yaml/MergeYamlVisitor.java b/rewrite-yaml/src/main/java/org/openrewrite/yaml/MergeYamlVisitor.java
index a938e6b235..2cf6897b2f 100644
--- a/rewrite-yaml/src/main/java/org/openrewrite/yaml/MergeYamlVisitor.java
+++ b/rewrite-yaml/src/main/java/org/openrewrite/yaml/MergeYamlVisitor.java
@@ -23,6 +23,7 @@
 import org.openrewrite.style.GeneralFormatStyle;
 import org.openrewrite.style.Style;
 import org.openrewrite.yaml.MergeYaml.InsertMode;
+import org.openrewrite.yaml.internal.BlockScalarUtils;
 import org.openrewrite.yaml.tree.Yaml;
 
 import java.util.ArrayList;
@@ -380,9 +381,9 @@ private Yaml.Sequence mergeSequence(Yaml.Sequence s1, Yaml.Sequence s2, P p, Cur
     }
 
     private Yaml.Scalar mergeScalar(Yaml.Scalar y1, Yaml.Scalar y2) {
-        String s1 = y1.getValue();
-        String s2 = y2.getValue();
-        return !s1.equals(s2) && !acceptTheirs ? y1.withValue(s2) : y1;
+        String s1 = BlockScalarUtils.getBody(y1);
+        String s2 = BlockScalarUtils.getBody(y2);
+        return !s1.equals(s2) && !acceptTheirs ? BlockScalarUtils.withBody(y1, s2) : y1;
     }
 
     /**
diff --git a/rewrite-yaml/src/test/java/org/openrewrite/yaml/CoalescePropertiesTest.java b/rewrite-yaml/src/test/java/org/openrewrite/yaml/CoalescePropertiesTest.java
index 629d682803..dfa1aa06a1 100644
--- a/rewrite-yaml/src/test/java/org/openrewrite/yaml/CoalescePropertiesTest.java
+++ b/rewrite-yaml/src/test/java/org/openrewrite/yaml/CoalescePropertiesTest.java
@@ -376,4 +376,52 @@ void applyToWithExclusion() {
           )
         );
     }
+
+    @Test
+    void skipsCoalesceWhenInnerMappingContainsBlockScalar() {
+        rewriteRun(
+          spec -> spec.recipe(new CoalesceProperties(null, null)),
+          yaml(
+            """
+              outer:
+                inner:
+                  java_opts: >-
+                    -Da=1
+                    -Db=2
+                  after: tail
+              """
+          )
+        );
+    }
+
+    @Test
+    void skipsCoalesceWhenInnerValueIsBlockScalar() {
+        rewriteRun(
+          spec -> spec.recipe(new CoalesceProperties(null, null)),
+          yaml(
+            """
+              outer:
+                inner: |
+                  line one
+                  line two
+              """
+          )
+        );
+    }
+
+    @Test
+    void skipsCoalesceWhenBlockScalarNestedDeeperInSubEntry() {
+        rewriteRun(
+          spec -> spec.recipe(new CoalesceProperties(null, null)),
+          yaml(
+            """
+              outer:
+                inner:
+                  details:
+                    script: |
+                      echo hello
+              """
+          )
+        );
+    }
 }
diff --git a/rewrite-yaml/src/test/java/org/openrewrite/yaml/MergeYamlTest.java b/rewrite-yaml/src/test/java/org/openrewrite/yaml/MergeYamlTest.java
index 527492eb5e..f31c047a09 100644
--- a/rewrite-yaml/src/test/java/org/openrewrite/yaml/MergeYamlTest.java
+++ b/rewrite-yaml/src/test/java/org/openrewrite/yaml/MergeYamlTest.java
@@ -3752,4 +3752,45 @@ void mergeYamlPreservesInlineCommentOnDocumentEnd() {
         );
     }
 
+    @Test
+    void overwriteFoldedStripBlockScalarPreservesEnvelope() {
+        rewriteRun(
+          spec -> spec.recipe(new MergeYaml("$", "key: replaced\n", false, null, null, null, null, null)),
+          yaml(
+            """
+              key: >-
+                line one
+                line two
+              after: tail
+              """,
+            """
+              key: >-
+                replaced
+              after: tail
+              """
+          )
+        );
+    }
+
+    @Test
+    void overwriteLiteralKeepBlockScalarPreservesEnvelope() {
+        rewriteRun(
+          spec -> spec.recipe(new MergeYaml("$", "key: replaced\n", false, null, null, null, null, null)),
+          yaml(
+            """
+              key: |+
+                line one
+                line two
+
+              after: tail
+              """,
+            """
+              key: |+
+                replaced
+
+              after: tail
+              """
+          )
+        );
+    }
 }