diff --git a/lib/lyx2lyx/lyx_2_1.py b/lib/lyx2lyx/lyx_2_1.py
index d327d87a36..20d87badd0 100644
--- a/lib/lyx2lyx/lyx_2_1.py
+++ b/lib/lyx2lyx/lyx_2_1.py
@@ -2989,18 +2989,18 @@ def convert_beamerblocks(document):
                         break
                     ertcontlastline = lastertend - 3
                     while True:
-                        if document.body[ertcontfirstline].startswith("<"):
+                        if document.body[ertcontfirstline].lstrip().startswith("<"):
                             # This is an overlay specification
                             # strip off the <
-                            document.body[ertcontfirstline] = document.body[ertcontfirstline][1:]
-                            if document.body[ertcontlastline].endswith(">"):
+                            document.body[ertcontfirstline] = document.body[ertcontfirstline].lstrip()[1:]
+                            if document.body[ertcontlastline].rstrip().endswith(">"):
                                 # strip off the >
-                                document.body[ertcontlastline] = document.body[ertcontlastline][:-1]
+                                document.body[ertcontlastline] = document.body[ertcontlastline].rstrip()[:-1]
                                 # Convert to ArgInset
                                 document.body[parbeg] = "\\begin_inset Argument 1"
-                            elif document.body[ertcontlastline].endswith("}"):
+                            elif document.body[ertcontlastline].rstrip().endswith("}"):
                                 # strip off the }
-                                document.body[ertcontlastline] = document.body[ertcontlastline][:-1]
+                                document.body[ertcontlastline] = document.body[ertcontlastline].rstrip()[:-1]
                                 # divide the args
                                 ertcontdivline = ertcontfirstline
                                 tok = document.body[ertcontdivline].find('>{')
@@ -3025,12 +3025,12 @@ def convert_beamerblocks(document):
                                                                             document.body[ertcontdivline][tok + 2:]]
                             # Convert to ArgInset
                             document.body[parbeg] = "\\begin_inset Argument 1"
-                        elif document.body[ertcontfirstline].startswith("{"):
+                        elif document.body[ertcontfirstline].lstrip().startswith("{"):
                             # This is the block title
-                            if document.body[ertcontlastline].endswith("}"):
+                            if document.body[ertcontlastline].rstrip().endswith("}"):
                                 # strip off the braces
-                                document.body[ertcontfirstline] = document.body[ertcontfirstline][1:]
-                                document.body[ertcontlastline] = document.body[ertcontlastline][:-1]
+                                document.body[ertcontfirstline] = document.body[ertcontfirstline].lstrip()[1:]
+                                document.body[ertcontlastline] = document.body[ertcontlastline].rstrip()[:-1]
                                 if ertcontfirstline < ertcontlastline:
                                     # Multiline ERT. Might contain TeX code.  Embrace in ERT.
                                     document.body[parend : parend + 1] = [
diff --git a/status.21x b/status.21x
index 0f05bc7ad3..07e3e4e9c3 100644
--- a/status.21x
+++ b/status.21x
@@ -67,6 +67,8 @@ What's new
 
 - Fix conversion of beamer block titles ending with non-ERT insets to 2.1 format.
 
+- Fix conversion of beamer blocks with preceding or trailing blanks.
+
 - Add \justification parameter when converting to 2.1 format (avoids when
   converting back to 2.0 format).