diff --git a/hedis.cabal b/hedis.cabal
--- a/hedis.cabal
+++ b/hedis.cabal
@@ -1,5 +1,5 @@
 name:               hedis
-version:            0.12.7
+version:            0.12.8
 synopsis:
     Client library for the Redis datastore: supports full command set,
     pipelining.
diff --git a/src/Database/Redis/Commands.hs b/src/Database/Redis/Commands.hs
--- a/src/Database/Redis/Commands.hs
+++ b/src/Database/Redis/Commands.hs
@@ -260,6 +260,7 @@
 xinfoStream, -- |Get info about a stream. The Redis command @XINFO@ is split into 'xinfoConsumers', 'xinfoGroups', and 'xinfoStream'. Since Redis 5.0.0
 xdel, -- |Delete messages from a stream. Since Redis 5.0.0
 xtrim, -- |Set the upper bound for number of messages in a stream. Since Redis 5.0.0
+inf, -- |Constructor for `inf` Redis argument values
 
 -- * Unimplemented Commands
 -- |These commands are not implemented, as of now. Library
diff --git a/src/Database/Redis/ManualCommands.hs b/src/Database/Redis/ManualCommands.hs
--- a/src/Database/Redis/ManualCommands.hs
+++ b/src/Database/Redis/ManualCommands.hs
@@ -1194,3 +1194,6 @@
             NoArgs -> []
             Maxlen max -> ["MAXLEN", encode max]
             ApproxMaxlen max -> ["MAXLEN", "~", encode max]
+
+inf :: RealFloat a => a
+inf = 1 / 0
diff --git a/src/Database/Redis/Types.hs b/src/Database/Redis/Types.hs
--- a/src/Database/Redis/Types.hs
+++ b/src/Database/Redis/Types.hs
@@ -39,7 +39,10 @@
     encode = pack . show
 
 instance RedisArg Double where
-    encode = pack . show
+    encode a
+        | isInfinite a && a > 0 = "+inf"
+        | isInfinite a && a < 0 = "-inf"
+        | otherwise = pack . show $ a
 
 ------------------------------------------------------------------------------
 -- RedisResult instances
diff --git a/test/Test.hs b/test/Test.hs
--- a/test/Test.hs
+++ b/test/Test.hs
@@ -357,6 +357,7 @@
     zrevrangeWithscores "key" 0 1                     >>=? [("v3",42),("v2",2)]
     zrangebyscore "key" 0.5 1.5                       >>=? ["v1"]
     zrangebyscoreWithscores "key" 0.5 1.5             >>=? [("v1",1)]
+    zrangebyscoreWithscores "key" (-inf) inf          >>=? [("v1",1.0),("v2",2.0),("v3",42.0)]
     zrangebyscoreLimit "key" 0.5 2.5 0 1              >>=? ["v1"]
     zrangebyscoreWithscoresLimit "key" 0.5 2.5 0 1    >>=? [("v1",1)]
     zrevrangebyscore "key" 1.5 0.5                    >>=? ["v1"]