diff --git a/doc/software-manual.tex b/doc/software-manual.tex
index 248ae055c26eb2cf8a137ae9d4819615cbe04407..3be3237eb2690622bd7aa72480fd88c6d2da4e4b 100644
--- a/doc/software-manual.tex
+++ b/doc/software-manual.tex
@@ -2891,7 +2891,7 @@ Value shall be in the range 1..8.
 \Option{ALFStrength} &
 %\ShortOption{\None} &
 \Default{1.0} &
-Enables control of ALF filter strength. The parameter scales the magnitudes of the ALF filter coefficients for both luma and chroma. Typical range of the parameter is between 0 and 1.
+Enables control of ALF filter strength. The parameter scales the magnitudes of the ALF filter coefficients for both luma and chroma. Valid values are in the range 0.0 to 1.0.
 \\
 
 \Option{CCALF} &
diff --git a/source/App/EncoderApp/EncAppCfg.cpp b/source/App/EncoderApp/EncAppCfg.cpp
index ef8868a739b84dba49b628d3614baed66ece64f4..98d1895ba6c16a8281db19613152c945b49195b7 100644
--- a/source/App/EncoderApp/EncAppCfg.cpp
+++ b/source/App/EncoderApp/EncAppCfg.cpp
@@ -1377,7 +1377,7 @@ bool EncAppCfg::parseCfg( int argc, char* argv[] )
   ("EnsureWppBitEqual",                               m_ensureWppBitEqual,                      false, "Ensure the results are equal to results with WPP-style parallelism, even if WPP is off")
   ( "ALF",                                             m_alf,                                    true, "Adaptive Loop Filter\n" )
 #if JVET_T0064
-  ("ALFStrength", m_alfStrength, 1.0, "Adaptive Loop Filter strength. The parameter scales the magnitudes of the ALF filter coefficients for both luma and chroma.")
+  ("ALFStrength", m_alfStrength, 1.0, "Adaptive Loop Filter strength. The parameter scales the magnitudes of the ALF filter coefficients for both luma and chroma. Valid range is 0.0 <= ALFStrength <= 1.0")
 #endif
   ( "CCALF",                                           m_ccalf,                                  true, "Cross-component Adaptive Loop Filter" )
   ( "CCALFQpTh",                                       m_ccalfQpThreshold,                         37, "QP threshold above which encoder reduces CCALF usage")
@@ -2738,6 +2738,13 @@ bool EncAppCfg::xCheckParameter()
     msg( WARNING, "****************************************************************************\n");
     m_dualTree = false;
   }
+#if JVET_T0064
+  if (m_alf)
+  {
+    xConfirmPara(m_alfStrength < 0.0, "ALFStrength is less than 0. Valid range is 0.0 <= ALFStrength <= 1.0" );
+    xConfirmPara(m_alfStrength > 1.0, "ALFStrength is greater than 1. Valid range is 0.0 <= ALFStrength <= 1.0" );
+  }
+#endif
   if (m_ccalf && (m_chromaFormatIDC == CHROMA_400))
   {
     msg( WARNING, "****************************************************************************\n");