diff --git a/requirements.txt b/requirements.txt
index 4e45dc9b..28435d09 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,7 +6,7 @@ bibtexparser>=1.2.0            # Generates bibtex
 kaleido == 0.1.0.post1; platform_system == "Windows"  # export plotly.py figures as static images
 kaleido == 0.2.0; platform_system=="Linux" or platform_system=="Darwin"
 matplotlib >= 3.4.3            # Plotting
-numpy>=1.20.1                  # Library used for arrays
+numpy>=1.20.1, <2.0.0          # Library used for arrays
 openpyxl >= 3.0.7              # Extract data from xlsm files
 pandas>=1.4.0, <2.1.0          # Powerful data structures for data analysis, time series, and statistics.
 pip>=9                         # The PyPA recommended tool for installing Python packages.
diff --git a/setup.py b/setup.py
index 8bb73a14..7c82c658 100644
--- a/setup.py
+++ b/setup.py
@@ -20,7 +20,7 @@
         "kaleido==0.1.0.post1;platform_system=='Windows'",
         "kaleido==0.2.0;platform_system=='Linux' or platform_system=='Darwin'",
         'matplotlib>=3.4.3',
-        'numpy>=1.20.1',
+        'numpy>=1.20.1, <2.0.0',
         'openpyxl>=3.0.7',
         'pandas>=1.4.0, <2.1.0',
         'pip>=9',