diff --git a/CHANGELOG.md b/CHANGELOG.md
index d71651050..0494eaeda 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,6 +33,7 @@ All notable changes to this project will be documented in this file.
 - [#1773] - Auto set flagWideCodes on FontInfo wide character adding
 - [#1769] - Do not mark getter+setter as colliding (#xxx suffix)
 - [#1801] - Flex SDK not required on commandline when Flex compilation is disabled
+- Multiname - performance issues
 
 ## [15.0.0] - 2021-11-29
 ### Added
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/abc/types/Multiname.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/abc/types/Multiname.java
index a17666ea3..6ab314fac 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/abc/types/Multiname.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/abc/types/Multiname.java
@@ -377,7 +377,7 @@ public class Multiname {
                 }
             }
 
-            if (fullyQualifiedNames != null && fullyQualifiedNames.contains(DottedChain.parseWithSuffix(name))) {
+            if (fullyQualifiedNames != null && !fullyQualifiedNames.isEmpty() && fullyQualifiedNames.contains(DottedChain.parseWithSuffix(name))) {
                 DottedChain dc = getNameWithNamespace(abc.constants, withSuffix);
                 return dontDeobfuscate ? dc.toRawString() : dc.toPrintableString(true);
             }
@@ -396,7 +396,7 @@ public class Multiname {
             return isAttribute() ? "@*" : "*";
         } else {
             String name = constants.getString(name_index);
-            if (fullyQualifiedNames != null && fullyQualifiedNames.contains(DottedChain.parseWithSuffix(name))) {
+            if (fullyQualifiedNames != null && !fullyQualifiedNames.isEmpty() && fullyQualifiedNames.contains(DottedChain.parseWithSuffix(name))) {
                 DottedChain dc = getNameWithNamespace(constants, withSuffix);
                 return dontDeobfuscate ? dc.toRawString() : dc.toPrintableString(true);
             }