diff --git a/lib/Lacuna/DB/Result/Building/GasGiantLab.pm b/lib/Lacuna/DB/Result/Building/GasGiantLab.pm
index 6b9a52d2..7cb8f39e 100644
--- a/lib/Lacuna/DB/Result/Building/GasGiantLab.pm
+++ b/lib/Lacuna/DB/Result/Building/GasGiantLab.pm
@@ -20,6 +20,7 @@ before has_special_resources => sub {
 };
 
 use constant controller_class => 'Lacuna::RPC::Building::GasGiantLab';
+use constant max_instances_per_planet => 1;
 
 use constant university_prereq => 19;
 
diff --git a/lib/Lacuna/DB/Result/Building/TerraformingLab.pm b/lib/Lacuna/DB/Result/Building/TerraformingLab.pm
index c4253745..e151bd63 100644
--- a/lib/Lacuna/DB/Result/Building/TerraformingLab.pm
+++ b/lib/Lacuna/DB/Result/Building/TerraformingLab.pm
@@ -20,6 +20,7 @@ before has_special_resources => sub {
 };
 
 use constant controller_class => 'Lacuna::RPC::Building::TerraformingLab';
+use constant max_instances_per_planet => 1;
 
 use constant university_prereq => 18;