diff --git a/commands/exists.sh b/commands/exists.sh
index 737280c..5fc6970 100755
--- a/commands/exists.sh
+++ b/commands/exists.sh
@@ -14,7 +14,7 @@ the_command="aws ${S3_PROFILE} ${ENDPOINT_APPEND} s3api head-object --bucket ${S
 echo $the_command
 
 # Verify file existence.
-sh -c $the_command
+sh -c "$the_command"
 
 # XXX: we are just checking the error code, but should check the result for a 404, and raise error in other cases
 if [ $? == 0 ]
diff --git a/commands/ls.sh b/commands/ls.sh
index 624d4da..2c50afb 100755
--- a/commands/ls.sh
+++ b/commands/ls.sh
@@ -12,7 +12,7 @@ the_command="aws ${S3_PROFILE} ${ENDPOINT_APPEND} s3 ls s3://${S3_BUCKET}/${FILE
 echo $the_command
 
 # Verify file existence.
-output=$(sh -c $the_command)
+output=$(sh -c "$the_command")
 
 echo $output
 
diff --git a/commands/rm.sh b/commands/rm.sh
index 604dffe..6b99c9c 100755
--- a/commands/rm.sh
+++ b/commands/rm.sh
@@ -12,7 +12,7 @@ the_command="aws ${S3_PROFILE} ${ENDPOINT_APPEND} s3 rm s3://${S3_BUCKET}/${FILE
 echo $the_command
 
 # Verify file existence.
-output=$(sh -c $the_command)
+output=$(sh -c "$the_command")
 
 echo $output
 
diff --git a/commands/sync.sh b/commands/sync.sh
index 8942f26..bc79073 100755
--- a/commands/sync.sh
+++ b/commands/sync.sh
@@ -7,4 +7,4 @@ the_command="aws ${S3_PROFILE} ${ENDPOINT_APPEND} s3 sync ${SOURCE_DIR:-.} s3://
 echo $the_command
 
 # Sync path.
-sh -c $the_command
+sh -c "$the_command"